The present invention relates to systems for providing heated fluids, and in particular to an exothermic fluid heater for utilization with in-situ lining or patching of pipes or the like. The preferred embodiment of the present invention utilizes a xe2x80x9cchemical heaterxe2x80x9d in the form of a cartridge containing an exothermic agent such as sodium hydroxide (caustic) soda, or the like, which, when infused into water, releases heat in the form of an exothermic reaction.
In the preferred embodiment of the invention, a cartridge is provided which contains the exothermic material. Water or the like is then directed through said cartridge so that the exothermic material dissolves, providing a solution of water infused with the exothermic material. The solution is heated by virtue of the exothermic reaction, said solution passing out of the cartridge and into a bladder located in a pipe, filling same. Situated about the bladder is a patch or sleeve of material including heat cured resin, which is urged to line the pipe by virtue of the bladder inflating, while simultaneously heated to cure same by virtue of the heated solution.
Upon curing of the resin, the bladder is deflated and the fluid drained or otherwise disposed of, with the cured resin sleeve or patch remaining in place lining the pipe. The bladder may then be removed.
While the exemplary embodiment of the present invention illustrates the use of sodium hydroxide as the exothermic material, it is noted that other materials may likewise be utilized with satisfactory results. Further, the exothermic reaction may be enhanced via the use of a catalyst such as aluminum or other metal or material.
It has been known that combining certain compositions, including sodium hydroxide and water, can cause an exothermic reaction which creates heat. In the many applications, exothermically created heat is often an undesirable byproduct; nonetheless, there is prior art which teaches the utilization of exothermically created heat to provide a chemical heater. However, the known prior art uses do not contemplate, suggest, or otherwise teach the system of the present invention.
A list of patents which may have some pertinence to the present invention include:
In current, known inversion methods of lining or spot repairing of pipe, a thermosetting resin-impregnated sleeve is situated about a generally cylindrical bladder, which bladder is filled with a fluid such as water to urge the sleeve about the inner diameter of the pipe to be lined or patched. As the resin is cured via thermal energy, it is often necessary to utilized heated water to fill the bladder, the heat of the water also curing the resin. In past methods, the fluid filling the bladder is heated via a boiler, furnace or the like to provide the thermal energy to cure the resin. Alternatively, infra red heaters, (U.S. Pat. No. 4,135,958), UV, and U.S. Pat. No. 5,937,910 teaches ultrasonic energy to cure the resin.
U.S. Pat. Nos. 3,663,335 and 3,307,997 teach the utilization of combustible fuel elements to heat an adhesive for joining pipes.
U.S. Pat. No. 4,430,988 teaches the use of sodium hydroxide as an exothermic heater agent, enhanced with aluminum ingots, for providing heated fluid for heating a diver under water.
U.S. Pat. No. 4,573,447 teaches a xe2x80x9cChemical Heaterxe2x80x9d utilizing sodium hypochlorite to heat a pad for warming a user.
The utilization of boilers, furnaces, infrared heaters, ultrasonic energy devices or the like to heat the thermosetting resin in pipe lining processes requires expensive equipment which may require training to operate, or may be dangerous or only be utilized with predetermined installations. What is not shown in the prior art is a system for heating thermosetting resin in situ within a pipeline, which is relatively inexpensive to implement and utilize, and which is flexible as to the circumstances of use.
The present invention contemplates a system for heating fluid utilized in the curing of resin in lining a pipe, which is more cost effective, faster, and easier to implement.
The present invention comprises a system for heating water to cure a resin impregnated liner or patch for lining or patching a pipe in situ, utilizing a chemical heater in the form of a cartridge containing an exothermic agent, such as sodium hydroxide (caustic soda) or some other substance which, when mixed with water or another fluid, releases heat, providing a heated solution. The heated solution is then directed to a bladder having a heat-cured resin impregnated liner situated thereabout, which bladder is then filled with the heated solution to urge the liner about the inner diameter of a pipeline, so as to position the liner and heat same to cure the resin. Once cured, the liner hardens to form a ridged inner wall of the pipe.
The current working embodiment of the invention utilizes a cartridge formed of PVC pipe having first and second ends and a chamber formed therein, the pipe three inches in diameter and about 32 inches long. Attached to the first end is a water hose, which engages a check valve at the unit. From the check valve, the inside of the unit contains about a xc2xcxe2x80x3 pipe, about 14 inches long, which has xe2x85x9xe2x80x3 flow apertures formed along its length. The second end of the cartridge comprises a cap about 5xe2x80x3 long which is threadingly attached to the first end. The second end of the unit has situated therein has a metal sieve with a filtering agent such as cheesecloth, the second end having emanating therefrom a hose connection which engages a hose which runs to a cylindrical bladder, for example, eight inches in diameter, about four feet long, which bladder has a drainage hose emanating from the opposite end.
In use, the bladder has removably placed thereupon a resin impregnated sleeve (of thermosetting resin), of felt or the like. Alternatively, a patch may be utilized in lieu of a sleeve. The bladder and sleeve (or patch) are placed within a pipeline at the desired position to repair or line the pipe. The cartridge is filled with caustic soda (sodium hydroxide) or some other exothermic composition. Water or some other fluid is then urged into the first end of the cartridge, which passes into the cartridge via the inner pipe, dissolving the sodium hydroxide, which dissolved solution passes through the sieve and filtering medium (cheesecloth), and into the bladder so as to inflate same.
In the exemplary bladder, it would take around fifteen gallons to inflate same. The solution becomes heated due to exothermic energy, which heat is retained by the water for several hours; as the resin is heat cured, the sleeve begins to harden with the bladder in its inflated state, urging the sleeve (or patch) against the inner wall of the pipe. After the resin has cured, the water is drained from the bladder via the drain hose, and the bladder pulled out, leaving the repaired pipe with the sleeve intact.
In the above example, two pounds of caustic soda (99% sodium hydroxide) is utilized per gallon of water, creating an exothermic heat of about 122 degrees Fahrenheit, although the temperature can be vary significantly with different concentrations. The use of other compositions, or the addition of other materials, such as, for example, aluminum, can increase the heat reaction.
It is therefore an object of the present invention to provide a method of lining or repairing passageways utilizing a chemical heater.
It is another object of the present invention to provide a system for curing thermosetting resin utilizing an exothermic reaction.
It is another object of the present invention to provide a cartridge system for mixing and forming an exothermic heater solution.
It is another object of the present invention to provide a method of lining pipe utilizing a cartridge system for providing a heated solution for inflating the bladder, so as to position a resin impregnated liner or patch, while heat curing the liner or patch with said heated solution.
Lastly, it is an object of the present invention to provide a method and system for lining passageways utilizing an exothermic cartridge heater system.